Did Apple's (AAPL) mammoth $17B bond sale mark the top for bonds? Ten-year Treasury yields bottomed for the year at about 1.62% right at the time of the offering and have gone vertical since (currently at 2.16%). A back-of-the-envelope calculation finds the company pocketing $724M in savings over the life of the paper by borrowing at the end of April vs. the end of May. TLT-7.6%, LQD-3.7% during May.